Forward-facing aircraft floodlight placement is currently limited to small areas of fixed structure, landing gear, landing gear doors, or extendable lights—see FIGS. 1 and 2. Traditional floodlights are incandescent or halogen, parabolic aluminized reflector (PAR) lamps.
Recently, high-intensity discharge (HID) lamps have been substituted for traditional PAR-46- and PAR-64-sized lamps. While the HID lamps are somewhat smaller for a given output, than the older PAR lamps, the packaging requirements are similar and have required placement within the traditional aircraft locations.
Traditional aircraft locations for forward lighting represent several engineering challenges. Any equipment mounted on the landing gear is subject to damage and wear from airflow, driven water, fluid leakage, shock loads, vibration, and mechanical stress from failing components or ground equipment contact. Placing extendable or gear-mounted lighting in the airstream increases aerodynamic drag. During the landing phase of flight, aerodynamic drag within reason is not a significant problem. However, any extra drag after take-off, while climbing out, is harmful.
Landing lights are used for added conspicuity whenever the aircraft is below a defined altitude. This is true both out-bound and inbound, as well as in an orbiting pattern. This defined altitude ranges from 18,000 to 10,000, feet based on local requirements. In many cases an aircraft is operating below the altitude that requires switching on a landing light yet prior to lowering the landing gear. Lights mounted in the wing root/strakelet area or retractable lights are normally used before the landing gear is lowered.